Currently, various kinds of small-sized antennas are developed, to be applied to various kinds of hand-held electronic devices (e.g. the mobile phone or the notebook computer) or to the wireless transmission device (e.g. the AP). For example, the planar inverse-F antenna (PIFA) that has a light structure as well, as a good transmission efficiency and can be easily disposed on the inner wall of the hand-held electronic device, has, been widely used for various kinds of hand-held electronic devices, the notebook computer or the wireless communication device.
The current planar inverse-F antenna has a narrower bandwidth. Because the frequency of the PIFA will drift under different environments, the fine tuning for the frequency segment thereof needs to be performed under different environments. This will greatly influence the manufacturing process of the PIFA, i.e. greatly increasing the cost of the mold.
In order to overcome the drawbacks in the prior art, an antenna and the method for adjusting the operation bandwidth thereof are provided. The particular design in the present invention not only solves the problems described above, but also is easy to be implemented. Thus, the present invention has the utility for the industry.